Travel from India(Kolkata) to Japan(Osaka) via Kunming by China Easter Airlines and back after 7days

Departure
Kolkata to Osaka , 20 Oct ,total travel time 11hrs 35min
By China Eastern MU 556 | Boeing 737-800.Flight has one stop at Kunming,China.Change over time is 2hrs.
The flight from Kunming reaches Osaka in 7hrs 10min
This Flight has a technical stop at Shanghai-Pu Dong Apt(PVG) for 1hr 20mins


Return

Osaka to Kolkata , 28 Oct total travel time 20hrs 35mim
By China Eastern MU 748 | Boeing 737-700
Osaka to Kunming takes 8hrs 55min.
This Flight has a technical stop at Shanghai-Pu Dong Apt(PVG) for 2hrs 5mins

Change of planes at Kunming | Connection time: 9h 15m
Reches Kolkata in 2hrs 25min.
Do I need Transit Visa??